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Biomedical subjects

W W Campbell

Publications and source records attributed to W W Campbell.

At least 19 recordsLinked to original sources
PubMed2001

Randomized controlled trial of IVIg in untreated chronic inflammatory demyelinating polyradiculoneuropathy.

OBJECTIVE: To determine the efficacy of IV immunoglobulin (IVIg) given patients with untreated chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). METHODS: A randomized, double-blind, multicenter, investigator-initiated study compared IVIg (Aventis Behring LLC, King of Prussia, PA) with placebo (5% albumin). On days 1, 2, and 21, IVIg (1 g/kg) or placebo was given. The primary outcome measure was the change in muscle strength from baseline to day 42, using the average muscle score (AMS). Secondary outcome measures included change from baseline AMS at days 10 and 21, the Hughes' functional disability scale, forced vital capacity (FVC), and nerve conduction studies (NCS) of four motor nerves (median, ulnar, peroneal, and tibial). RESULTS: The patients (n = 33) were randomized. Of these, 30 (14 women, 16 men, aged 54 +/- 20 years, range 13 to 82) received IVIg and 23 were given placebo (12 women, 11 men, aged 50 +/- 18 years, range 23 to 73). Baseline AMS values of the groups were similar (IVIg 7.06 +/- 1.31 versus placebo 7.28 +/- 1.18, p = 0.53). There were two dropouts in placebo group and one in the IVIg group. Mean AMS improved at day 42 comparing IVIg with placebo (0.63 versus -0.1, p = 0.006). Improved strength was seen by day 10. The placebo group lost strength over this same interval. In the IVIg, 11 subjects improved by the functional disability scale; none worsened. This differed (p = 0.019) from those in the placebo-treated group (two improved, two got worse, remainder unchanged). Forced vital capacity did not improve with IVIg treatment. IVIg improved ulnar motor distal latency (p = 0.005), tibial distal compound muscle amplitude (p = 0.003), and peroneal nerve conduction velocity (p = 0.03). CONCLUSIONS: IVIg improves strength in patients with untreated CIDP by day 10 with continued benefit through day 42; more than one third improve by at least a functional grade on a disability scale. This study provides data supporting IVIg as the initial treatment for CIDP.

Adolescent↗
PubMed2001

Relationships of plasma C-peptide and gender to the urinary excretion of inositols in older people.

PURPOSE: The urinary excretions of myo-inositol and D-chiro-inositol are elevated in diabetes, and have been suggested as possible markers or effectors of insulin action. The aim of the present study was to measure the urinary excretion of these compounds, and to assess possible relationships with the metabolic control of glucose, in older, non-diabetic men and women. SUBJECTS: 32 older (age range 54-71 yrs), moderately overweight (body mass index 29.1 +/- 0.4 kg/m2, mean +/- SEM), non-diabetic men (n = 17) and women (n = 15). METHODS: 75 g oral glucose tolerance testing was done the day after all subjects had consumed nutrient-defined menus for five days. Plasma samples were analyzed for the concentrations of glucose, insulin, and C-peptide, and the 180-minute area under the curve (AUC) for each of these compounds was calculated. Samples from 24-hour urine collections were analyzed for the concentrations of myo-inositol, D-chiro-inositol, L-chiro-inositol, and pinitol. RESULTS: The fasting glucose, insulin, and C-peptide, and the AUC for glucose and insulin, were not different between men and women. C-peptide AUC was greater in the men versus the women (p < 0.001). The median urinary excretions (micromol/g creatinine) of myo-inositol (p < 0.001), D-chiro-inositol (p < 0.001), L-chiro-inositol (p < 0.05), and pinitol (p < 0.001) were higher, and the myo-inositol:D-chiro-inositol ratio was lower (p < 0.001), in the men versus women. For all subjects combined, C-peptide AUC was positively correlated with the urinary excretion of each of the measured inositols, as well as the myo-inositol:D-chiro-inositol ratio. The correlations between C-peptide AUC and these inositols were strongly influenced by the co-linear relationship between C-peptide AUC and gender. CONCLUSIONS: Collectively, these data show that older, moderately overweight, non-diabetic men and women with gender-related differences in glucose-stimulated C-peptide AUC, an indirect indicator of insulin secretion, also display differences in the urinary excretion of myo-inositol, D-chiro-inositol, L-chiro-inositol, and pinitol. The gender-related difference in the myo-inositol:D-chiro-inositol ratio suggests that, while the urinary excretion of all of the inositols measured were higher in the men than the women, the difference was more pronounced for D-chiro-inositol.

Aged↗
PubMed2000

Neuromyotonia: autoimmune pathogenesis and response to immune modulating therapy.

BACKGROUND: Neuromyotonia (NMT) has been postulated to be an autoimmune channelopathy, probably by affecting voltage gated potassium channels (VGKC) leading to excitation and abnormal discharges [Sinha et al., Lancet 338 (1991) 75]. OBJECTIVE: To report three patients with NMT who had other associated immune-mediated conditions, i.e., myasthenia gravis, thymoma and various types of peripheral neuropathies. One patient had peripheral neuropathy and involvement of pre- and post-synaptic neuromuscular junction. RESULTS: All three patients had evidence of polyneuropathy and neuromyotonic discharges on electrodiagnostic studies. Elevated acetylcholine receptor antibodies were noted in all patients and malignant thymoma was found in two patients with metastasis. All three patients showed moderate to marked response to plasma exchange. CONCLUSIONS: These findings strongly suggest a humoral autoimmune pathogenesis of NMT, probably by K(+) channel involvement, affecting acetylcholine quantal release and postsynaptic membrane. Clinicians should be aware of this association of immune-mediated conditions in NMT patients and marked improvement with plasma exchange.

Adult↗
PubMed2000

Aged human muscle demonstrates an altered gene expression profile consistent with an impaired response to exercise.

The gene expression profile of skeletal muscle from healthy older (62-75 years old) compared with younger (20-34 years old) men demonstrated elevated expression of genes typical of a stress or damage response, and decreased expression of a gene encoding a DNA repair/cell cycle checkpoint protein. Although the expression of these genes was relatively unaffected by a single bout of resistance exercise in older men, acute exercise altered gene expression in younger men such that post-exercise gene expression in younger men was similar to baseline gene expression in older men. The lack of response of muscle from older subjects to resistance exercise was also apparent in the expression of the inflammatory response gene IL-1beta, which did not differ between the age groups at baseline, but increased within 24 h of the exercise bout only in younger subjects. Other genes with potentially important roles in the adaptation of muscle to exercise, specifically in the processes of angiogenesis and cell proliferation, showed a similar response to exercise in older compared with younger subjects. Only one gene encoding the multifunctional, early growth response transcription factor EGR-1, showed an opposite pattern of expression in response to exercise, acutely decreasing in younger and increasing in older subjects. These results may provide a molecular basis for the inherent variability in the response of muscle from older as compared with younger individuals to resistance training.

Adult↗
PubMed1999

Effect of resistance training with or without chromium picolinate supplementation on glucose metabolism in older men and women.

The effect of 12 weeks of resistance training (RT) with or without chromium picolinate (Cr-pic) supplementation on glucose tolerance was assessed in moderately overweight older men and women (age, 62 +/- 4 years; body mass index [BMI], 29.1 +/- 2.5 kg/m2). Seventeen men and 15 women were randomized to groups that consumed either 17.8 micromol chromium per day (924 microg Cr/d) as Cr-pic or a placebo (<0.1 microg Cr/d) while performing RT twice weekly. For all 32 subjects combined, fasting glucose increased but there were no changes in insulin or C-peptide concentrations after 12 weeks of RT. In response to an oral glucose challenge, the glucose and C-peptide areas under the curve (AUCs) were unchanged, whereas there was a 19% decrease in the insulin AUC (from 68 +/- 53 to 55 +/- 29 x 10(3) pmol/L/180 min, P = .045). The RT responses for the fasting concentration or AUC for glucose, insulin, or C-peptide were not influenced by Cr-pic. The decrease in the insulin AUC without any change in insulin secretion, as evidenced by a lack of change in the C-peptide AUC, suggests enhanced insulin clearance from the circulation with RT. Collectively, these data suggest that RT decreases the insulin response following an oral glucose challenge in older moderately overweight men and women without affecting glucose tolerance. The data also suggest that the decrease in circulating insulin may result from an increase in insulin clearance, not a decrease in insulin secretion. High-dose Cr-pic supplementation had no effect on any measure of glucose metabolism during RT.

Aged↗
PubMed1999

Differential effect of resistance training on the body composition and lipoprotein-lipid profile in older men and women.

The effects of a 12-week resistance exercise training (RT) program on body composition and serum lipid concentrations were assessed in weight-stable, moderately overweight older men (n = 18) and women (n = 17) aged 54 to 71 years with a body mass index (BMI) of 26 to 36 kg/m2. Following RT, the men had a significant increase in fat-free mass (FFM) and a decrease in percent body fat (%BF) and fat mass (FM), whereas the women demonstrated no change, resulting in significant time-by-sex interactions for FFM (P = .002), %BF (P = .006), and FM (P = .005). There were no changes in total cholesterol (Chol), low-density lipoprotein cholesterol (LDL-C), or triacylglycerol (Tg) due to RT. However, following RT, high-density lipoprotein cholesterol (HDL-C) increased (0.06+/-0.02 mmol/L) in the men and decreased (0.09+/-0.03 mmol/L) in the women (time-by-sex interaction, P = .0004). The Chol/HDL-C ratio decreased (0.36+/-0.11) in the men and increased (0.29+/-0.10) in the women (time-by-sex interaction, P = .0001). For all subjects combined, the changes in HDL-C and the Chol/HDL-C ratio were not related to any changes in body fat stores (ie, %BF or FM), suggesting that RT may potentially alter the lipoprotein-lipid profile in older weight-stable men and women. In conclusion, although the changes in the lipoprotein-lipid profile were small, the men had a significantly increased HDL-C level and decreased Chol/HDL-C ratio, while the women demonstrated opposite changes.

Aged↗
PubMed1999

Effects of an omnivorous diet compared with a lactoovovegetarian diet on resistance-training-induced changes in body composition and skeletal muscle in older men.

BACKGROUND: Very limited data suggest that meat consumption by older people may promote skeletal muscle hypertrophy in response to resistance training (RT). OBJECTIVE: The objective of this study was to assess whether the consumption of an omnivorous (meat-containing) diet would influence RT-induced changes in whole-body composition and skeletal muscle size in older men compared with a lactoovovegetarian (LOV) (meat-free) diet. DESIGN: Nineteen men aged 51-69 y participated in the study. During a 12-wk period of RT, 9 men consumed their habitual omnivorous diets, which provided approximately 50% of total dietary protein from meat sources (beef, poultry, pork, and fish) (mixed-diet group). Another 10 men were counseled to self-select an LOV diet (LOV-diet group). RESULTS: Maximal strength of the upper- and lower-body muscle groups that were exercised during RT increased by 10-38% (P < 0.001), independent of diet. The RT-induced changes in whole-body composition and skeletal muscle size differed significantly between the mixed- and LOV-diet groups (time-by-group interactions, P < 0. 05). With RT, whole-body density, fat-free mass, and whole-body muscle mass increased in the mixed diet group but decreased in the LOV- diet group. Type II muscle fiber area of the vastus lateralis muscle increased with RT for all men combined (P < 0.01), and the increase tended to be greater in the mixed-diet group (16.2 +/- 4.4 %) than in the LOV diet group (7.3 +/- 5.1%). Type I fiber area was unchanged with RT in both diet groups. CONCLUSION: Consumption of a meat-containing diet contributed to greater gains in fat-free mass and skeletal muscle mass with RT in older men than did an LOV diet.

Aged↗
PubMed1999

Changes in power with resistance training in older and younger men and women.

BACKGROUND: Muscle power diminishes with increasing age and inactivity. The capacity for older adults to increase muscle power with resistance exercise has not been examined; therefore, we examined the influence of progressive resistance training (PRT) on muscle power output in 17 men and women aged 56-66 years, and compared their responses to 15 men and women aged 21-30 years. METHODS: All subjects performed 12 weeks of PRT at a workload equivalent to 80% of the one repetition maximum (1RM). All training and assessments of 1RM and power were made on Keiser pneumatic resistance machines. Subjects performed five exercises, three sets per exercise, twice weekly. Muscle power was measured (isotonically) at resistances equivalent to 40, 60, and 80% of the 1RM, on the knee extension and arm pull machines. RESULTS: All subjects increased arm pull power similarly at 40 and 60% of 1RM, independent of age or sex. There was not a significant increase in arm pull power at 80% of 1RM. Older and younger subjects also had similar absolute increases in leg extensor power at 40 and 60% of 1RM, but men responded with greater absolute gains than women at these percentages (p < .05). The increase in leg extensor power at 80% of 1RM was similar in all groups. Older and younger subjects increased strength similarly in all exercises except the left knee extension. Independent of age, men increased strength more than women in all exercises except the double leg press. CONCLUSIONS: These data demonstrate that individuals in their sixth decade can still improve muscle power (and strength); however, men may realize greater absolute gains than women.

Adult↗
PubMed1999

Effects of resistance training and chromium picolinate on body composition and skeletal muscle in older men.

The effects of chromium picolinate (CrPic) supplementation and resistance training (RT) on skeletal muscle size, strength, and power and whole body composition were examined in 18 men (age range 56-69 yr). The men were randomly assigned (double-blind) to groups (n = 9) that consumed either 17.8 micromol Cr/day (924 microg Cr/day) as CrPic or a low-Cr placebo for 12 wk while participating twice weekly in a high-intensity RT program. CrPic increased urinary Cr excretion approximately 50-fold (P < 0.001). RT-induced increases in muscle strength (P < 0.001) were not enhanced by CrPic. Arm-pull muscle power increased with RT at 20% (P = 0.016) but not at 40, 60, or 80% of the one repetition maximum, independent of CrPic. Knee-extension muscle power increased with RT at 20, 40, and 60% (P < 0.001) but not at 80% of one repetition maximum, and the placebo group gained more muscle power than did the CrPic group (RT by supplemental interaction, P < 0.05). Fat-free mass (P < 0.001), whole body muscle mass (P < 0.001), and vastus lateralis type II fiber area (P < 0.05) increased with RT in these body-weight-stable men, independent of CrPic. In conclusion, high-dose CrPic supplementation did not enhance muscle size, strength, or power development or lean body mass accretion in older men during a RT program, which had significant, independent effects on these measurements.

Aged↗
PubMed1999

Effects of heavy-resistance training on hormonal response patterns in younger vs. older men.

To examine the adaptations of the endocrine system to heavy-resistance training in younger vs. older men, two groups of men (30 and 62 yr old) participated in a 10-wk periodized strength-power training program. Blood was obtained before, immediately after, and 5, 15, and 30 min after exercise at rest before and after training and at rest at -3, 0, 6, and 10 wk for analysis of total testosterone, free testosterone, cortisol, growth hormone, lactate, and ACTH analysis. Resting values for insulin-like growth factor (IGF)-I and IGF-binding protein-3 were determined before and after training. A heavy-resistance exercise test was used to evaluate the exercise-induced responses (4 sets of 10-repetition maximum squats with 90 s of rest between sets). Squat strength and thigh muscle cross-sectional area increased for both groups. The younger group demonstrated higher total and free testosterone and IGF-I than the older men, training-induced increases in free testosterone at rest and with exercise, and increases in resting IGF-binding protein-3. With training the older group demonstrated a significant increase in total testosterone in response to exercise stress along with significant decreases in resting cortisol. These data indicate that older men do respond with an enhanced hormonal profile in the early phase of a resistance training program, but the response is different from that of younger men.

Adrenocorticotropic Hormone↗
PubMed1998

Focal atrophy of the multifidus muscle in lumbosacral radiculopathy.

A patient with compelling clinical and electrodiagnostic evidence of a right L5 radiculopathy had focal atrophy of the multifidus at the appropriate level, which served to confirm the radicular nature of the process. The multifidus muscles are innervated by a single root, in contrast to the polysegmental innervation of the rest of the paraspinal muscle mass. Imaging studies may complement needle electromyography in the evaluation of this important structure.

Electromyography↗
PubMed1998

Acute hormonal responses to heavy resistance exercise in younger and older men.

The purpose of this investigation was to examine the acute responses of several hormones [total and free testosterone (TT and FT, respectively), adrenocorticotropic hormone (ACTH), cortisol (C), growth hormone (GH), and insulin (INS)] to a single bout of heavy resistance exercise (HRE). Eight younger [30-year (30y) group] and nine older [62-year (62y) group] men matched for general physical characteristics and activity levels performed four sets of ten repetitions maximum (RM) squats with 90 s rest between sets. Blood samples were obtained from each subject via an indwelling cannula with a saline lock pre-exercise, immediately post-exercise (IP), and 5, 15 and 30 min post-exercise. Levels of TT, FT, ACTH, C and lactate significantly increased after HRE for both groups. Pre-HRE pairwise differences between groups were noted only for FT, while post-HRE pairwise differences were found for TT, FT, GH, glucose and lactate. Area under the curve analysis showed that the 30y group had a significantly higher magnitude of increase over the entire recovery period (IP, 5, 15, and 30 min post-exercise) for TT, FT, ACTH and GH. Few changes occurred in the INS response with the only change being that the 62y group demonstrated a decrease IP. Lactate remained elevated at 30 min post-HRE. This investigation demonstrates that age-related differences occur in the endocrine response to HRE, and the most striking changes appear evident in the FT response to HRE in physically active young and older men.

Adrenocorticotropic Hormone↗
PubMed1998

Augenblickdiagnose.

The process of making a diagnosis is integral to the practice of medicine, but diagnostic reasoning is rarely taught as a specific point. In most instances, experienced clinicians use a method of generating and testing hypotheses, finally selecting the hypothesis that best explains the clinical picture. Occasionally, especially distinctive physical signs allow augenblickdiagnose, a term that means "diagnosis in the blink of an eye." The process is too rapid to have followed a hypothesis testing method. Similarly, key fragments of history often permit very rapid diagnosis. The ability to make a snap diagnosis based on characteristic physical signs or snippets of clinical information relies on familiarity with certain critical clinical information. The reader is invited to try to augenblickdiagnose several cases.

Adult↗
PubMed1998

Changes in muscle morphology, electromyographic activity, and force production characteristics during progressive strength training in young and older men.

Effects of a 10-week progressive strength training program composed of a mixture of exercises for increasing muscle mass, maximal peak force, and explosive strength (rapid force production) were examined in 8 young (YM) (29+/-5 yrs) and 10 old (OM) (61+/-4 yrs) men. Electromyographic activity, maximal bilateral isometric peak force, and maximal rate of force development (RFD) of the knee extensors, muscle cross-sectional area (CSA) of the quadriceps femoris (QF), muscle fiber proportion, and fiber areas of types I, IIa, IIb, and IIab of the vastus lateralis were evaluated. Maximal and explosive strength values remained unaltered in both groups during a 3-week control period with no training preceding the strength training. After the 10-week training period, maximal isometric peak force increased from 1311+/-123 N by 15.6% (p <.05) in YM and from 976+/-168 N by 16.5% (p <.01) in OM. The pretraining RFD values of 4049+/-791 N*s(-1) in YM and 2526+/-1197 N*s(-1) in OM remained unaltered. Both groups showed significant increases (p < .05) in the averaged maximum IEMGs of the vastus muscles. The CSA of the QF increased from 90.3+/-7.9 cm2 in YM by 12.2% (p <.05) and from 74.7+/-7.8 cm2 in OM by 8.5% (p <.001). No changes occurred in the muscle fiber distribution of type I during the training, whereas the proportion of subtype IIab increased from 2% to 6% (p < .05) in YM and that of type IIb decreased in both YM from 25% to 16% (p < .01) and in OM from 15% to 6% (p < .05). The mean fiber area of type I increased after the 10-week training in YM (p < .001) and OM (p < .05) as well as that of type IIa in both YM (p < .01) and OM (p < .01). The individual percentage values for type I fibers were inversely correlated with the individual changes recorded during the training in the muscle CSA of the QF (r=-.56, p < .05). The present results suggest that both neural adaptations and the capacity of the skeletal muscle to undergo training-induced hypertrophy even in older people explain the gains observed in maximal force in older men, while rapid force production capacity recorded during the isometric knee extension action remained unaltered during the present mixed strength training program.

Adult↗
PubMed1997

Energy requirement for long-term body weight maintenance in older women.

The total dietary energy requirement of healthy, free-living older women was examined by determining the total energy intake (TEI) required for long-term body weight maintenance in nine women aged (mean +/- SD) 67 +/- 9 years (range, 56 to 78). For 14 weeks, each woman consumed defined amounts of foods and beverages prepared at a General Clinical Research Center (GCRC) to provide 0.8 g protein.kg-1.d-1 and a nonprotein energy ratio of 40% fat to 60% carbohydrate. Adjustments to TEI were made to keep body weight within +/-0.5 kg of each woman's starting body weight. All women were asked to maintain their habitual level of daily activity, and the energy cost of physical activity was estimated using the Yale Physical Activity Survey (YPAS). Resting energy expenditure (REE) was measured with each woman in the postabsorptive state just after awakening, using an indirect calorimeter at baseline and week 14. The energy requirement expressed as the ratio of TEI to REE was 1.82 +/- 0.15, a value 21% higher (P < .001) than the energy allowance of 1.5 x REE suggested for women beyond age 50 years in the 1989 Recommended Dietary Allowances (RDAs). Using the RDAs equation to predict REE from body weight (pREE), the ratio of TEI to pREE was 1.73 +/- 0.18 (P < .005, comparison with 1.50 x REE). Estimates of the energy expenditure for physical activity (EEPA) based on the energy intake-balance data and the YPAS data were similar (3.18 +/- 0.92 and 3.14 +/- 1.42 MJ/d, respectively) for the group of women, but were more variable on an individual basis. Results of this long-term energy balance study suggest that the RDAs underestimate the dietary energy requirement of older women.

Aged↗